I had sex on March 10th with one man and with another on the 19th of March and a week after that. Turned out I was pregnant, I didn't find out till I was a little over 4 months because my period was always irregular and I had bleeding in April so I didn't think anything of it. So my first scan is what gave me my due date which was Dec 11th, I had my baby on Dec 14th after my OB stretched my cervix at my appointment I went into labor within 24 hours. I had 4 scans altogether, towards 3rd trimester baby was measuring little but came out 6lbs 4ounces. Also a boy I don't know if that matters.